Kathryn Zickuhr, a Pew Internet Project research specialist and co-author of the report, explained in a statement:

Americans are not currently all that eager to share explicitly their location on social media sites, but they are taking advantage of their phones' geolocation capabilities in other ways. Smartphone owners are using their phones to get fast access to location-relevant information on-the-go.

Here is how it breaks down:

 28 percent of cell owners use their phones for directions or recommendations based on their current location.

 9 percent of Internet users configure social-media services (i.e. Facebook, Twitter, or LinkedIn) so that their locations are automatically included in their posts on those services.

 5 percent of cell phone owners check in to locations using geosocial services such as Foursquare or Gowalla.

These numbers jump significantly when you account for smartphone owners only, probably because these sorts of utilities are really built for smartphones. Therefore, they're easier to use with more graphically enhanced and faster apps with 3G/4G connectivity.

For example, Pew found that 12 percent of smartphone owners use geosocial services, and as much as 55 percent use their smartphones for getting directions and recommendations based on current locations.

As far as demographics go, it's not much of a surprise that smartphone owners between the ages of 18 and 49 are more likely than those over 50 to use either geosocial or location-based services on their phones. However, Pew didn't find any significant differences among social-media users grouped by age regarding automatic location-tagging.

For reference, Pew's survey is based on the responses of 2,277 American adults aged 18 and over who were interviewed via landline and cell phones in English and Spanish between April 26 and May 22.